A French restaurant in Wellington is being hounded by activists protesting against its popular foie gras starter.

Placard-wielding animal-rights protesters have taunted Le Canard restaurant in Thorndon every weekend for more than six months, its owners say.

Foie gras is a traditional French delicacy made from duck or goose livers that have been engorged by overfeeding them with fat-covered grains.

It is illegal to farm the birds using the force-feeding method in New Zealand, and fresh foie gras cannot be imported. However, a handful of Wellington restaurants use legal tinned imports.

Pascal Bedel, whose family own Le Canard, said he was not concerned when activists began chanting, holding up banners and handing out pamphlets outside his Murphy St restaurant last year.

But then negative comments began appearing on websites and he started receiving calls every couple of days asking if he would take the dish off the menu.

"Since December I've got people coming here every couple of days and they protest during my service. They are here all the time and they push, push, push."

Mr Bedel said he aimed to give diners an authentic French experience, which included the "expensive and delicious" dish of his home region of southwest France. So he would never take the popular dish off his menu.

"I don't make the law in New Zealand. Go to complain to them, but not to me.

"You can't talk to these people because they're fanatical."

Hans Kriek, executive director of animal-rights group Safe, called foie gras a "barbaric" product, and said he knew about regular protests at a Wellington restaurant.

"It's appalling that people even think that they can continue selling the product that is well recognised within the animal-welfare world."

The force-feeding was "one of the cruellest procedures around", and citing "tradition" was no excuse for preserving it, he said.

Dominion Post food critic David Burton did not believe the practice was cruel, saying "ducks are very gross eaters".

The smooth-textured product was "like a very rich version of chicken-liver pate" and was so delicious that he ate it twice in one day from a Michelin-starred restaurant in France.

"It's ancient in France. I don't think it's something they're going to give up, so people may as well get over it."

WHAT IS FOIE GRAS?

A buttery pate made from the engorged liver of a duck or goose.

Feeding tubes are put down the birds' necks to overfeed them with grains boiled in fat.

Some farms produce "ethical foie gras" by allowing the birds to gorge themselves, capturing them before they fly away.

Wellington restaurants charge more than $30 for an entree-sized portion.